Implantable medical devices (IMDs) are devices designed to be implanted into a patient. Some examples of these devices include cardiac function management (CFM) devices such as implantable pacemakers, implantable cardioverter defibrillators (ICDs), cardiac resynchronization devices, and devices that include a combination of such capabilities. The devices are typically used to treat patients using electrical or other therapy or to aid a physician or caregiver in patient diagnosis through internal monitoring of a patient's condition. The devices may include one or more electrodes in communication with one or more sense amplifiers to monitor electrical heart activity within a patient, and often include one or more sensors to monitor one or more other internal patient parameters. Other examples of implantable medical devices include implantable diagnostic devices, implantable drug delivery systems, or implantable devices with neural stimulation capability.
Additionally, some IMDs detect events by monitoring one or more electrical heart activity signals. In addition to electrical events, CFM devices may measure and monitor one or more hemodynamic parameters related to heart chamber filling or contraction. These parameters may provide an indication of the metabolic need of a patient for a particular level of cardiac output, for example. The parameters may be useful to track the progression of disease, such as congestive heart failure, for example. Measuring and monitoring the parameters may also be useful to detect a sudden episode such as acute myocardial ischemia. As technology used in IMDs increases, the devices are able to collect data from multiple types of sensors. However, this can complicate the task of data management for caregivers.